51 Spanning Tree Commands

spanning-tree mst cost

This command configures the path cost on a spanning instance in the Multiple Spanning Tree. Use the no form to restore the default.

Syntax

spanning-tree mst instance_id cost cost no spanning-tree mst instance_id cost

instance_id - Instance identifier of the spanning tree. (Range: 0-4094, no leading zeroes)

cost - Path cost for an interface. (Range: 1-200,000,000) The recommended range is -

Ethernet: 200,000-20,000,000

Fast Ethernet: 20,000-2,000,000

Gigabit Ethernet: 2,000-200,000

Default Setting

By default, the system automatically detects the speed and duplex mode used on each port, and configures the path cost according to the values shown below. Path cost “0” is used to indicate auto-configuration mode.

Ethernet – half duplex: 2,000,000; full duplex: 1,000,000; trunk: 500,000

Fast Ethernet – half duplex: 200,000; full duplex: 100,000; trunk: 50,000

Gigabit Ethernet – full duplex: 10,000; trunk: 5,000

Command Mode

Interface Configuration (Ethernet, Port Channel)

Command Usage

Each spanning-tree instance is associated with a unique set of VLAN IDs.

This command is used by the multiple spanning-tree algorithm to determine the best path between devices. Therefore, lower values should be assigned to interfaces attached to faster media, and higher values assigned to interfaces with slower media.

Use the no spanning-tree mst cost command to specify auto-configuration mode.

Path cost takes precedence over interface priority.

Example

Console(config)#interface ethernet ethernet 1/5

Console(config-if)#spanning-tree mst 1 cost 50

Console(config-if)#

Related Commands

spanning-tree mst port-priority(51-17)

51-16

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Accton Technology ES4548D, ES4524D, 24/48-Port manual Spanning-tree mst cost, Spanning-tree mst port-priority51-17